If the bags are the ones I'm thinking of, that have a plastic slider on the top that is supposed to help seal the air out, the ones I had like that did not seal and when you squeezed the air out the seal would break or the slider would pop off. For me they were total garbage, in fact garbage bags with a loop lanyard with a spring loaded lok cord device is what I use on white water canoe trips. The seal has never failed, if the bag does i replace it cheap with another garbage bag.

That sounds just like what I bought last year and used. Very waterproof, but not very scuff proof. On about day 5 I found a big scuff that went all the way throught the bag. The best use I have seen was a guy last year that had put one of these inside a big green Army duffle. He said it had worked great for years. Good luck.